Roller leveler with upper-roller adjusting means



March 25, 1958 F. K. MAUST ROLLER LEVELER WITH UPPERQROLLER ADJUSTING MEANS Original Filed July 28, 1949 2 Sheets-Sheet 1 3* g 3 g g NM mmvron Fnsb ERICK/(M19057 H TTOR/VE Y March 25', 1958 F. K. MAus'r I 2,827,945

ROLLER LEVELER WITH UPPER-ROLLER ADJUSTING MEANS Original Filed July 28, 1949 2 Sheets-Sheet 2 na] 1 "-14; J24

71/72/11 49 ATTORNEY 1 2,827,945 ROLLER LEVELER WITH UPPER-ROLLER ADJUSTING MEANS Frederick K. Maust, Queens Village,'N. Y.

Original application July 28, 1949, Serial No. 107,157,

now Patent No. 2,638,143, dated May 12, 1953. Dividedand this application February 17, 1953, Serial No. 337,265

3 Claims. (Cl. 153-107) This invention relates to roller levelers for flattening and straightening sheet and strip material. More especially, it relates to a method of and apparatus for flattening and straightening work-material in roller levelers of the so-called double tilt type as covered by my United States Patent No. 2,132,426, issued October 11, 1938.

A double tilt roller leveler consists primarily of an upper and a lower row of straightening rolls positioned in staggered relation one with respect to the other and constructed in such a way as to subject the work-material passing between the rows of straightening rolls first to transverse waves or corrugations of gradually increasing magnitude on the entry side of the machine, then to waves of maximum magnitude between the centrally located straightening rolls, and finally to waves of gradually decreasing magnitude or amplitude on the exit side for flattening out the material.

To obtain eifective leveling action, straightening rolls of comparatively small diameter must be employed which are supported between their ends by means of supporting rolls or back-up rolls. The levelers now in use have the straightening roll groups and their associated supporting rolls at the entry and exit side, respectively, mounted on bridge-typewings which are tiltable as complete units into the desired angular tilting positions. Each wing is tilted around a fulcrum represented by one of the straightening rolls mounted on the wing which requires extreme accuracy in manufacture to obtain the necessary precise alignment and makes maintenance difficult and expensive, because the complete bank of straightening rolls and their back-up rolls must be removed for any work to be done on either wing.

One object of the present invention is to subdivide the straightening rolls and supporting rolls of one of the two roll banks into groups, to pivotally mount the end supports carrying the entry and exit straightening roll groups and to similarly divide their associated supporting rolls and mount them in independently adjustable yokes, but employing a common fulcrum for the end supports and yokes of each group.

Another object is to provide means for displacing said end supports of one group of straightening rolls and the yokes of their associated supporting rolls simultaneously around their common fulcrum by moving the centrally located straightening rolls and their supporting rolls into working position, while at all times maintaining all supporting rolls in contact with their straightening rolls.

A still further object is to provide simple but efiicient wedge means for accomplishing the double tilt of the straightening rolls and to thereby decrease the over-all height of the machine.

Another object is to provide means for individually aligning each of said end supports and each of said yokes to simplify the manufacture, assembly as well as maintenance.

Another object is to provide a novel height adjustment for adjusting the roll opening between the two banks of straightening rolls for different thicknesses of work-material and for lifting one of the straightening roll banks an appreciable distance for convenient access during assembly and maintenance without increasing the over-all height of the roller leveler.

These and other objects whichwill be pointed out in the specifications and especially in the claims to follow, I at- *tain by means of my invention disclosed in the drawings,

wherein:

Fig. 1 is a left hand front view of the leveler shown in Fig. 2, partly in section, wherein the lower central supporting roll bank is shown in section along line 1a-1n Fig. 2, and the lower right hand supporting roll bank is shown in section along line 1b-1b Fig. '2.

Fig. 2 is .a side View of a roller leveler, partly broken away for clearness with top and bottom straightening and supporting rolls in neutral, parallel positions.

Fig. 3 is a fragmentary top view to illustrate the wedgerleflecting mechanism for the upper straightening or workrolls.

Fig. 4 is a somewhat diagrammatic side view showing the work-rolls and backing rolls in double tilt position.

Fig. 5 is a partial sectional view along line 5--5 Fig. 2, depicting part of one work-roll end support and its manner of pivoting.

Fig. 6 is a fragmentary top view of the height adjusting mechanism in the direction of arrows 66 of Fig. 1.

Fig. 7 showsa top view of a supporting roll yoke alone; and

Fig. 8 isa section along line 88 of Fig. 4.

This application is a division of my prior application Serial Number 107,157, filed July 28, 1949, since issued in Patent Number 2,638,143, issued May 12, 1953.

Referring to Figs. 1 and 2, the leveler comprises a lower base 11 and an upper frame 12 connected by two tie-rods 13 on the operating side, and two tie-rods 14 on the drive end. The generally rectangular base 11 carries at each corner roll housings which have received the numerals 15 on the operating end and 16 on the drive end.

The upper and lower rows of straightening rolls are "usually separately and individually driven by means of universal couplings secured to their drive ends 156,

spindles, gear box, speed reducer, and a hydraulic or electric prime mover (not shown), as it is well known 'in the art.

Double .tilt

The lower row of straightening rolls is shown divided into three distinct groups. Straightening rolls 17 and 18 form the middle or central group; straightening rolls 19, 20 and 21 at one end of the row of straightening rolls form the left-hand wing group; straightening rolls 22, 23, 24 at the other end of said row of straightening rolls form the right-hand wing group as best seen in Figs. 2 and 4.

All straightening rolls extend the full length between front roll housings 15 and rear roll housings '16 and are mounted in identical bearing brackets or end supports at front, and rear. The central straightening rolls 17 and 18 are journaled in front bearing bracket 25 and in an identical bearing bracket located between the rear roll housings 16. These bearing brackets or end supports 25 are provided with laterally extending cradle supports 26 and 27 for supporting left and right hand tiltable wings or bearing brackets 28 and 29 which rotatably carry the respective roll groups 19, 2t), 21 and 22, 23, 24 at their ends. Cradle supports 26 and 27 possess curvilinear supporting surfaces 30 and 31 for slidingly carrying respective wing supports or wing bearing brackets 28 and 29 having matching surfaces 32 and '33. Shafts 34 and 35 extend longitudinally between roll housingslS, 16 on the left and right hand sides of the leveler (Fig. 2) and may be journaled in eccentric bushings 36 and 37, respectively. These eccentricbushings may be turned in housings 15 and 16 in order to change the vertical and lateral locations of shafts 34 and 35 for aligning purposes. Pins 38 may serve to locate bushings 36 and 37 in their adjusted positions.

The straightening roll wings 28 and 29 are guided in suitable recesses of housings 15 and 16 and are oscillatably mounted on respectivefulcrum shafts 34 and 35 inbushings 36 and 37, respectively, as shown for the righthand wing 29 inFig. 5. The shaft 34 representsthe fulcrum situated outside their respective-groups of straightening rolls carried in wings 28 and 29.

Horizontal thrust loads on wings 28 and 29 normal to the axes of the straightening rolls; are also absorbed by vertical curvilinear sliding surfaces 39 and 40 which are in contact with the substantially straight, vertical sides 41 of central bearing blocks 25. In addition, the lower curvilinear surfaces 32 and 33 of wings 28 and 29 may be provided with tongues 42 which extend into matching grooves 43 of central bearing cradle supports 26 and 27 for further lateral guidance.

For the support of the slim straightening rolls, any number of supporting roll banks may be arranged along the straightening rolls between their ends. The supporting rolls are preferably, but not necessarily, placed in staggered relation to their associated straightening rolls in order to provide not only vertical, but also lateral support. Fig. 1 shows, for example, three identical banks of back-up rolls 158, 159, 160 for the lower straightening rolls.

These lower supporting roll or back-up roll banks are also divided into three distinct groups in a similar way as above described in connection with their associated straightening rolls. However, each of these supporting roll banks is actuated independently of the lower straightening roll bearing brackets. Furthermore, the left and right hand supporting roll yokes 44 and 45 carry three supporting rolls each, namely, 161, 162, 163 and 164, 165, 166, respectively, and the middle supporting roll hearing brackets or end supports designated as 46 carry also three supporting rolls 167, 168, 169, in contrast to their associated central straightening roll end supports 25 which only carry two straightening rolls. It will be evident that, for the proper vertical and lateral support of the straightening rolls, one more supporting roll will .be required in each bank than the number of straightening rolls to be supported. With the exception of one more back-up roll carried by the central section,.the construction of the wing and central bearing elements of the supporting roll bank is analogous to that of their associated straightening rolls.

As best seen in Figs. 4 and 7, the back-up roll groups 161, 162, 163 and 164, 165, 166 are journaled in respective wing asseblies 44 and which each consist of two bearing blocks 47 and 48 pivoted in eccentric bushings49 V ing roll bearing bracket 46 which also has curvilinear cradle supports 54 and for supporting the left and right hand supporting roll'wing assemblies 44 and 45 on the matching surfaces 51 of the traverse, analogous to the construction previously described in connection with the straightening roll wings 28 and 29. Traverse .51 and cradle supports 54 and 55 have tongues 56 and grooves 57, respectively, for lateral positioning (Fig. 8).

It should be noted that the arcuate surfaces 39 and 40 of the straightening roll wings 28 and 29, and the corresponding surfaces 52 of the supporting roll wing assemblies or yokes 44 and 45 have the longitudinal axes of respective fulcrum shafts 34 and 35 as their centers. The lower acruate surfaces 32 and 33 of the straightening roll wings and the corresponding acruate surfaces 51 of the supporting roll yokes 44 and 45 have the longitudinal axis of respective straightening rolls 21 and 24 as their centers.

Hence, when the central bearing brackets 25 of the straightening rolls and the central bearing brackets 46 of .or operating side of the leveler.

-ries a scale 75 for indicating the degree of tilt.

the back-up rolls are equally raised or lowered, the lower straightening roll wings 28, 29 and their associated backup roll yokes 44, 45 will be moved in unison around their respective fulcrum shafts 34 and 35. In other words, when raising these central bearing brackets 25 and 46 from their neutral'or original positions shown in Fig. 2, where all straightening rolls and back-up rolls lie in parallel horizontal planes, to the double tilted, position shown in Fig. 4, their straightening rolls 17 and 18 and associated back-up rolls 167, 168, 169 will be lifted together.

, Simultaneously, the pivoted wings 28 and 29 with irespective straightening roll groups 19, 20, 21 and 22, 2 3, 24 wil be tilted or oscilalted around fulcrum shafts 34 and 35, respectively, in such a way that straightening rolls 21 and 24 adjacent the middle group will be lifted as much as this middle group 17, 18; consequently, the

whereas the angles of tilt or inclination formed by the straightening rolls 19, 20'and 22, 23 may be identical and the apices of their angles of inclination will be directed toward the middle group. Thus the entry roll 19 will receive the work-material at a neutral or original level and said work-material will be gradually lifted to the higher straightening level of central rolls 18, 17 when passing over straightening rolls 20 and 21; the

reverse will be true on the exit side, where the straighten- ,ing level will be gradually dropped again to neutral, while the work-material passes rolls 24, 23, 22. The supporting roll groups 164, 165, 166 of the right wing and 161, 162, 163 ofthe left wing will be simultaneously similarly tilted as their associated straightening rolls and hence will follow these straightening rolls and remain in sup- .porting contact with them regardless of the magnitude of the angle of tilt, Fig. 4.

This simple and compact construction, which permits alignment and adjustment of each one of the several bearing brackets and wings, reduces the difficulties encountered with former leveling machines if it does not eliminate the same entirely.

The central bearing brackets 25 and 46 may be vertically adjusted or displaced with respect to said stationary fulcrums 34, 35 by any suitable means. The well-known screw-adjustment may be employed or, as shown in the drawings, the lifting of the central groups of lower straightening and back-up rolls and the tilting of wings 28, 29 and yokes 44, 45 into double tilted positions may be accomplished by means of wedges which has the advantage of space conservation and rigidity.

Lower sloping surfaces on straightening and supporting roll brackets 25 and 46 are in contact With respective wedges 59 and 60, which rest on base plates 61 fast to bed 62 0f base 11. Pilot pins 63 threaded into bases 61 may extend through suitable openings 64 of wedges 59 and 60 into matching cylindrical bores 65 of bearing blocks 25 and 46 to keep the adjusting elements in alignment. A screw 66 is threaded into each one of the wedges 59 and 60 (Fig.2). Screws 66are rotatably held in brackets 67 and actuated by means of bevel gears 68 fast to screws 66 and meshing bevel gears 69 fast to control shaft 70 which may be rotated by means of a handwheel 71 on the front Control shaft 70 is shown to be journaled in bearings 72, 73 and 74. The centralfront straightening roll bearing bracket 25 car- It rotatably supports indicator hand 76 actuated by a pin 77 fast to wedge 59, Fig. 2. V

While two continuous longitudinal fulcrum shafts 34 and 35 have been shown for the suspension of all straightening roll wings and supporting roll yokes, it is evident that a plurality 'of'short pivot bearings'may be employed instead, maintaining however all pivots in the same longikeep pins 84 in position.

tudinal axes of the present fulcrum shafts34 and 35,]re-

spectively. Thus saidwings and yokes would still have common longitudinal fulcrum axes which will be designated in short as fulcrumsff A Rotation of handwheel 71 results in the horizontal displacement of wedges 59 and 60 and, hence, in vertically moving the centrally located straightening and'supporting roll groups, and in simultaneously oscillating the entry and exit straightening and back-up roll groups around their respective fulcrurns 34 and 35 into any desired double tilted positions.

Deflection of upper straightening rolls To correct the mill-shaped of the work-material, certain portions thereof must be subjected to'preferential stretching. This is accomplished by deflecting the straightening rolls into a convex-concave or other shape which results in deeper transverse wave formations in the work-material along those portions which need stretching. The deflection of the straightening rolls is effected by moving their as the supporting rolls that their bearings are evenly loaded, in other words, that corner pressures are avoided when the straightening rolls are being deflected.

In the roller leveler shown, the upper bank of straightening rolls, characterized by the numeral 78, are defiectable.

Their ends are journaled in bearing blocks 79 Whose arcuate surfaces 80 are in contact with support saddles 81 secured to, or forming part of, the upper frame structure 12. Pivot arms 82 and 83 extend from upper frame 12 at each end of bearing blocks 79. Pins 84 are threaded into said pivot arms centrally to the straightening roll journals and extend into suitable bores 85 of straightening roll bearing blocks 79. Lock-nuts 86 are provided to The arcuate surfaces 80 have said pins 84 as centers and the solidly supported straighteningroll bearing blocks may therefore oscillate around pivot pins 84 whenever the straightening rolls are deflected.

Three banks or units of short back-up rolls 87, 88, 89 reinforce the upper straightening rolls 78. The three units are substantially alike and consist in supporting rolls 90 journaled in side bearing blocks 91 and 92 fast to a center element 93 which is provided with an arcuate surface 94 in contact with a similar surface on pivot saddle 95 whose upper sloping surface rests against wedge element 96. The latter is guided by pilot pins 97 which are threaded into a base plate 98 bolted as at 99 or otherwise secured to upper frame 12. Saddle 95 has respective brackets or pivot arms 100 and 101 at each of its ends. Pivot pins or pivot elements 102 are threaded into said brackets and secured by lock-nuts 103. Pivot pins 102 extend into bores of cross-bridges 104 which span the ends of bearing blocks 91 and 92 and are bolted or otherwise secured thereto. Arcuate surfaces 94 have pins 102 as their centers. A number of springs 105 with studs 106 threaded into base plate 98 are adjustable by means of nuts 107 and hold the several elements of each supporting roll unit together. The cradle support formed by bearing blocks 91, 92, center element 93, and cross-bridges 104 is thus rockably mounted and supporting rolls 90 of each bank may follow closely the straightening roll deflection contour.

Supporting roll units 87, 88, 89 may be moved toward or away from their straightening rolls 78 to deflect the latter by the horizontal movement of wedges '96 effected by means of control bar 108 and handle 109. Each backup roll unit has a separate operating connection with said control bar 108 comprising a lever 110 pin-connected to control bar 108 mounted in bracket 113 fast to the upper frame 12. The shaft 112.also carries a second control lever 114 which is normally operatively secured to shaft 112 by removable pin 115 extending through the hub of lever 114 into shaft 112. The end of lever 114 is pincsn ste o we 6 as a A h l 1 o m part of lever 114 and after removal pf pin 1 15,each wedge 96 maybe individuallygadjusted by saidhandle 116 independent of control bar'108.

Ordinarily it is desirable to deflect the straightening rolls 78 into either convex or concave contours. In other words, the centrally located supporting roll unit 88 is moved a greater distance towards or away from the straightening rolls 78'than the outside supporting units 87 and 89. This may be accomplished in various ways. The slopes of wedges 96 may differ, for instance, while the effective lengths of slotted operating levers 114 may be identical for all three supporting roll units; or the slopes of wedges 96 may be held constant andthe effective lengths of operating levers 114 may diifer.

Any other desired deflection contour may be produced, however, by removing one or all of the pins 115 and by adjusting the position as one or all of the wedges 96 of each supporting roll unit individually, employing handles 116.

While three supporting rollunits have been shown for the upper and lower straightening rolls for the purpose of illustration, it is understood that any desired number of supporting roll banks may be employed. Reference is made in this connection to my United States Patent No. 2,091,789 of August 31, 19,37.

The deflection arrangement shown has the advantages of low head-room requirements, rigidity, balanced bearing loads, possibility of quickly adjusting convex and concave deflection contours by the simultaneous movement of all supporting roll sections 87, 88,89 by means of handle 109 ,and of producing any desired shape by individually regulating each of the units by means of handles 116, and compact unit construction which simplifies maintenance, because each individual supporting roll unit may be removed as a Whole from the machine, because springs and studs 106 hold the several parts of the unit in assembled position.

Height adjustment For cleaning and maintenance purposes it is of great practical importance to be able toraise the upper straightening rolls as far away from the lower straightening rolls as possible. In the past, this has been accomplished by increasing the over-all height of the machine to create the necessary room for the desired lift. In addition to high and expensive housings and screw-down connections, the longitudinal inclination of the upper straightening rolls for stretching one margin of the work-material has also been very restricted. These shortcomings are eliminated in the construction shown in the drawings.

The four tie-rods 13, 13 and 14, 14 may be screwthreaded at both ends. Their upper ends may support the frame 12 in any suitable manner, such as between threaded nuts 117 and 118 and self-aligning thrust-bearings 119 and 120. Bushings 121 in housings 15 and 16 guide the tie-rods which extend through threaded sleeves 122 fast to base 11. Cross-brackets 12 3 and 124 in base 11 extend between and follow the vertical movements of tie-rods 14 at the drive end and tie-rods 13 at the front of the machine, respectively. Therefore, tierods 14, 14 and 13, 13 are rotatably supported in bearings 125 and 126 of brackets 123 and 124, respectively, which rest on threaded nuts 127 and 128 at the lower ends of tie-rods 14 and 13, respectively and serve to maintain tie-rods and cross-brackets in their relative positions.

Height adjustment shafts 129 and 130 extend longitudinally to the leveler and are journaled in several bearings, such as indicated at 131, 132, 133, 134 of brackets 123 and 124. It will be seen that hearing 134 of bracket 124 is free to move vertically in window 157 of base 11. At the drive-end of the machine, shafts 129, 130 carry worms 135 in mesh with worm-wheels 136 which are fast to tie-rods 14. At the front end, worms 137 are secured to sleeves 138 which are free to rotate on shafts 129 and 130 and carry one-half of jaw-clutches 139 (Figs. 1 and 6). Worms 137 are in mesh with worm-wheels 148 secured to tie-rods 13. The other halves 140 of the jaw-clutches are slidingly keyed to shafts 129 and 130 and are movable into and out of engagement with elements 139 by means of formed levers 141 pivoted in bracket 124 as at 142 and pin-connected to a cross-bar 143 which extends between levers 141. Crossbar 143 is pivotally connected at its approximate center to lever 144. A control lever 145 is pivotally mounted on bracket 146 fast to cross-bracket 124 and is pin-connected to lever 144 as at 147. Chain sprockets 149 and 150 may be keyed to shafts 129 and 130, respectively, and interconnected by chain 151 to rotate said shafts in unison. A gear motor 152 for driving shaft 130 may be flanged to motor bracket 153 which is secured to or forms a part of cross-bracket 124 and is free to move vertically in window 154 of base 11. Universal joints or flexible couplings 155 may be interposed in shafts 129 and 130 (Fig. 1) to provide flexibility.

When hand lever 145 is in the position shown in Fig. 1, the jaw-clutch halves 139 and 140 are separated and .worms 137 and their meshing Worm-wheels 148 on tierods 13 will remain stationary when shafts 129 and 130 are rotated by means of gear motor 152. When the jaw clutches 139-140 are brought into engagement by moving lever 145 to the right as viewed in Fig. 1, all four tie-rods 14, 14; 13, 13 will be rotated in unisornand the upper frame structure 12 with the upper straightening and supporting rolls will be raised or lowered uniformly depending on the direction of rotation of gear motor 152. In the first example, the jaw-clutch halves 139140 separated, the drive end of the upper frame 12 may be adjusted in the desired vertical direction, while the front end of the upper frame will remain stationary. Thus the upper straightening rolls may be longitudinally inclined with respect to the lower straightening rolls for stretching short margins of the work-material.

It will be noted that the height adjustment described not only employs the tie-rods 13, 13; 14, 14 directly for the vertical adjustment of the upper frame 12, permits longitudinal inclination of the straightening 'rolls by means of a simple clutch arrangement, utilizes a single motor for raising the straightening rolls uniformly or for longitudinally inclining the straightening rolls, but'utilizes the available space in the bed of the machinefor providing a lift of considerable magnitude without adding to the over-all height of the leveler.

Operation of leveler I V p The lower straightening'rolls and their associated supporting rolls are raised from their neutral positions shown in Fig. 2 into any desired double tilted position by rotating handwheel 71. If the work-materialrequires correction, the upper straightening rolls 78 are deflected into the necessary contour by manipulating controlbar 108 or by individually adjusting each of the upper-support roll units by means of handles 116 after first removing pins 115, or by a combination of these'rnethods. The upper bank or row of straightening rolls 78 is regulated in height for obtaining roll passes of the desired magnitudes by meansof gear motor 152, either uniformly by rotating all four tie-rods or spindles 13,14- withjawclutch 139149 in engagement, in" longitudinally inclined by disengaging clutch 139+140 and thus keeping the front spindles-13, -13 stationary. This-adjustment will depend on theeifectto be produced on the'workmaterial. 7 the outer roll groups at the end of the lower straightening roll row may beidenticalgthe same effect will be obtained whether the work-material is passed through'theleveler from left to right or vice-versav 1 When the operating direction is from left to right as viewed in Fig. 4, the entering'work-material will be received at a neutral level and subjected to wave formations of gradually increasing amplitude, while the level of the straightening path is also gradually raised until the workmaterial reaches lower straightening roll 21. Then maximum wave depth and maximum straightening level are -reached and maintained until the work-material has passed lower straightening roll 24." The subsequent rolls 23, 22 will then impart waves of decreasing amplitude and finally deliver the work-material in flat condition, while simultaneously therewith, the level of the straightening path is also gradually returned to its original neutral level.

While in the embodiment of my invention as disclosed, three straightening rolls have been shown as comprising each one of the tiltable roll groups at each end of the lower row of straightening rolls, and two straightening rolls as comprising the central or middle group, any de sired number of straightening rolls may be employed for each of said groups. For frequent reversing service, the symmetricalarrangement is preferred as shown, but for uni-directional straightening as is encountered, for instance, in'straightening coils, it may be desirable to have fewer straightening rolls in the pivotable wing sections at the entry side than at the exit side.

The principle of. employing supporting and straightening roll wings, pivotedat. one of their ends and vertically Becaus'ethe tilt or angle-of inclination of 7 y the supporting roll arrangements known in the art.

displaceableat the opposite, ends may be applied to any of Various other changes and modifications will be obvious to those skilled inthe art. I desire, therefore, that only such limitations shall be placed upon my invention as are specifically set forth in the appended claims.

I claim:

1. In a roller leveler, an upperframe for supporting a row of upper, straightening rolls, a base for supporting a cooperating row of lower straightening rolls mounted in staggered relation thereto, a pair of spaced-apart and screw-threaded spindles rotatably secured to one end of said upper frame, another pair of spaced-apart and screwthreaded spindles rotatablysecured, to the other end of said upper frame, nuts fast to said base and in threaded engagement with said spindles, a bracket for rotatably sustaining each of said two pairs of spindles below said nuts, and adjusting means' mounted on said brackets for rotating said spindles in said nuts to vertically displace said spindles and consequently said upper frame with respect to said base, said brackets and adjusting means-participating in the vertical displacement of said spindles.

2. In a roller leveleraccording to claim 1, wherein said adjusting means include clutch means for the selective actuation of one pair of said spindles only, in order to longitudinally inclinesaid upper frame, and its row of upper straightening rolls with respect to the row of lower straightening rolls supported by said base.

3. In a roller leveler comprising an upper frame and a lower base of substantially rectangular shapes, a first pair of spaced-apart and screw-threaded spindles rotatably secured at their upper ends to one side of said upper frame, a second pair of spaced-apart and screw-threaded spindles rotatably secured at their upper ends to the opposite side ofsaid upper frame, nuts fast to said base and in threaded engagement with said spindles, a bracket for each pair of said spindles, said brackets being located in said base and being adapted to participate in any vertical displacement of said spindles, motor driven actuating 'means mounted on one of said brackets for rotating said spindles including clutch means for the selective actuation of one pair of said spindles only.

References Qited in the file of this patent UNITED STATES PATENTS 1,697,090 Russell Jan. 1, 1929 1,822,119 Ungerer Sept. 8, 1931 1,959,492 Moses May 22, 1934 2,009,508 Maussnest July 30, 1935 2,219,163. Maussnest Oct. 22, 1940 

